's a lot less safe. so hopefully they're through it all. and what we also know, according to nbc news, is that it is just the one person that they're looking for. they thought for a while that they were looking for some accomplices and so on. this doesn't mean that they've caught anybody. it just means that they know who they're looking for, dzhokar tsarnaev, and -- >> tsarnaev. >> thank you maria, tsarnaev. but they're looking for him, and the hope is, the thinking is, and the hope is that he is still here in watertown. >> the thinking in terms of going door to door, scott, i guess it could be either, you know, tsarnaev is holding somebody hostage and hiding in their home or someone's hiding him in their home. they're going door to door in that region, this is like a 20-block radius, correct? >> that's about right. this is a town of about 32,000 people. it's fairly densely populated. so they do have a lot to look for and as we were looking at most of the homes, they're close together, from the areas that we've seen, a lot of single family homes, almost all single family homes. there'